This invention relates to top stops for limiting the upward movement of a slider in the operation of coupling or closing a slide fastener. More specifically, the invention relates to an improved top stop device for use in a slide fastener having continuous coupling elements made of a filamentary synthetic resin.
There are two well known types of top stops for use in the slide fasteners of the above defined class. One is formed by fusing the scoops of the coupling elements into the stops of desired shape. The other is formed by fusing separate pieces of a synthetic resin onto the respective coupling elements. The first type of top stops are generally flat in shape and are inevitably rather undersized, so that the stops are questionable as to their capability of positively limiting slider movement.
This capability is unquestioned in the second type of top stops. However, as the pair of top stops of this type repeatedly abut against each other just under the neck or separator of the slider body at the end of the fastener closing movement of the slider, either of the stops tend to be deformed or sagging. As a consequence, when the slider is held in place at a topmost or fully closed position on the coupling elements, the top stops may lose a proper angle relative to each other, that is, may become displaced from their predetermined relative positions, and hence make the downward movement of the slider extremely sluggish. For this reason, the slider is prohibited to start moving smoothly downwardly as the slide fastener is opened.